Improvement in manufacturing pyrqxvline articles



J. W. HYATT.

Manufacturing Pyruxyli'ne Articles.

Patented April 29. T8 73.

wire/442M? AM, P/IUTlI-LITHOGRAPHIC ca m."(ossamvs& mocsss) solvents,such as ether, alcohol, &c., are emmulate between the coating andthecore, theresels filled with sand. The porous molds when actly fit eacharticle, which is very difficult and expensive, and especially so in thecase of UNITED STATES" JOHN W. HYATT, OF ALBANY, NEW YORK.

IMPROVEMENTIN MANUFACTURING PVRQXVLINE ARTICLE-S.

Specification forming part of Letters Patent No. 138,254, dated April.29., 1873 application filed October 23, 1872.

To all whom it may concern:

Be it known that I, JOHN W. HYATT,0f the city and county of Albany,State of New York, have invented a certain Process in ManufacturingArticles from Compounds of Pyroxyline, of which the following is aspecification:

The invention relates more especially to the manufacture of articlesfrom pyroxyline or soluble cotton, where liquid solvents are employed inthe conversion thereof. When liquid ployed in the manufacture ofarticles from compounds of soluble cotton or pyroxyline, the materialshrinks greatly in drying, and is liable to become spongy and filledwith air-cells by reason of the rapid evaporation of the solvents andexpansion of the gases in the material. In articles which are coatedwith compounds of soluble cotton or pyroxyline the same results takeplace, while, in addition, small quantities of the gases resulting fromthe evaporation of the volatile solvents, accuby preventing the desiredclose and firm connection of the coating with the body of the article.Attempts have been made heretofore to avoid these imperfections bysubjecting such articles, immediately after they are formed, to pressurein porous'molds, or in vesthey are used, are required to be made toexfine and delicately-molded articles, which are almost certain to bedistorted when subjected to pressure in such molds. The use of sand, asabove stated, is also objectionable, as it does not possess sufficientmobility to prevent distortion of the more delicately-formed articles.The object of my improvement is to obviate these defects. The inventionconsists in the process of subjecting articles made of compounds ofsoluble cotton or pyroxyline, or coated therewith, to pressure in aclosed vessel by means of air or other suitable gas or liquid forcedtherein, which will properly absorb the solvent from the compound, whilethe article, of whatever form or configuration, is subjected to auniform pressure, which effecttually prevents the expansion of thematerial and the formation of air-cells without producin g the leastdistortion or derangement of the parts, while at the same time therapidity of the drying or seasoning process can be easily regulated.

In using my improved process I prefer air as the medium for applying thepressure, both on account of economy and the facility with which itabsorbs the solvent. The method I prefer is to placethe article,immediately after being molded or coated with the compound, in areceiver, and then force in air under sufficient pressure to prevent aircells forming. For this purpose a pressure of twelve atmospheres isgenerally sufficient, although a greater pressure will have no injuriouseffect on the article. The receiver being provided with adischarge-aperture, the rapidity of the drying can be controlled byregulating the amount of air passed through the vessel in contact withthe articles to be dried. Ordinarily the articles are not required toremain in the receiver longer than about thirty-six hours before thematerial will be sufficiently freed from the solvent to permit thearticles to be removed to the ordinary drying-room.

The accompanying drawing represents the apparatus I prefer to use when aliquid is employed as the compressing agent. Of this drawing, Figure Iis a sectional elevation of a vessel or flask for receiving the articlesto be dried under pressure. Fig. II is an outside elevation thereof atright angles to El g. I. Fig. III is a plan view of the same. Iiikeletters designate like parts in each of the figures. A represents thelower conical part of the flask, and b the pressure-pipe connecting itslower end with a force-pump of any suitable construction. 0 representsthe upper remov able part of the flask, provided with a circu larflange, c, fitting on a similar flange, a, formed on the lower part A.The upper part 0 is secured to the latter by a bail, d, fitting over thepart 0, and projecting with its ends through openings in the flanges ac, on the under side of which it is secured by wedge-keys 0, so as to bereadily attached and detached. The part 0 may, however, be secured tothe lower part by screw-bolts passing through the flanges a c, or in anyother suitable manner. E is a rubber ball valve, which prevents thereturn of the fluid when the case is removed from the force-pump.

The article to be dried is placed in the lower part A, upon a diaphragmmade of open cloth, stretchedupon a hoop to preventmarringthe article,when the upper part 0 is tightly secured to the lower. WVater,glycerine, turpentine, or a mixture of alcohol and water, or any otherliquid possessing a sufficient affinity for the solvent to readilyabsorb the same, is forced therein, by means of aforce-pump, until therequired pressure (which is the same as when air is used) is obtained.The air in the case, being compressed to, say, one-tenth its formerbulk, serves to retain ample pressurewithin the vessel, even though asmall quantity of the fluid should escape through the valve or packingbetween the two parts of the vessel. Articles allowed to remain in thevessel under this pressure for about thirty-six hours will besufficiently hardened, or the coating thereof, to permit of theirremoval from the vessel.

The rapidity of the drying process can be regulated by using a liquidpossessing a greater or less affinity for the solvent.

Claim.

In the manufacture of articles composed of compounds of pyroxyline orsoluble cotton, or of articles coated therewith, the process of subjecting the articles, when first formed or coated, and before drying, topressure in 'a vessel, by forcing therein air, alcohol, andwater, orother suitable fluid which will absorb the solvent from the formedarticle, the pressure on the surface preventing the expansion thereofand the formation of air-cells without dis torting the shape of thearticle, substantially as hereinbefore-set forth.

JOHN \V. HYATT.

Witnesses:

JAMES GRAY, A. A. SANBORN.

